Scalable and Optimal Security Allocation in Networks against Stealthy Injection Attacks

TL;DR

This paper presents a scalable, optimal method for allocating sensors in networked control systems to defend against stealthy injection attacks, minimizing attack impact with limited attacker knowledge.

Contribution

It introduces a novel optimal security allocation algorithm that is scalable and effective against stealthy attacks in interconnected network systems.

Findings

The algorithm effectively minimizes attack impact.

Scalable implementation demonstrated through numerical examples.

Provides a systematic approach for security resource allocation.

Abstract

This paper addresses the security allocation problem in a networked control system under stealthy injection attacks. The networked system is comprised of interconnected subsystems which are represented by nodes in a digraph. An adversary compromises the system by injecting false data into several nodes with the aim of maximally disrupting the performance of the network while remaining stealthy to a defender. To minimize the impact of such stealthy attacks, the defender, with limited knowledge about attack policies and attack resources, allocates several sensors on nodes to impose the stealthiness constraint governing the attack policy. We provide an optimal security allocation algorithm to minimize the expected attack impact on the entire network. Furthermore, under a suitable local control design, the proposed security allocation algorithm can be executed in a scalable way. Finally, the obtained results are validated through several numerical examples.